Rapid and sensitive detection of hazardous chemicals is essential for worker safety in industrial environments and for soldier safety in the field. In this work, we propose a physical coloration platform to passively amplify existing colorimetric sensing mechanisms. We outline a design process which can be targeted to an arbitrary colorimetric indicator and target and fabricate as a demonstration a sensor which produces noticeable color change on reaction with ammonia in the vapor phase.
Chemical warfare agents (CWAs) such as nerve and blister agents are expected to pose continuing and growing dangers for the Warfighter in the future. We investigate a novel chemical detection modality, based on a new platform for colorimetric detection of chemical threats incorporated in hollow fibers, which are miniature in two dimensions and extendable (“extrudable”) in the third dimension (along the fiber length). By exploring fibers, and films that can be scaled to a fiber geometry, we will enable a new fiber-based chemical threat detector that can serve in textiles worn by the Warfighter (e.g., uniform), as well as in non-worn textiles and an outlying fence or perimeter for early detection of a threat cloud near an expeditionary shelter, outpost, encampment, or base.
We have recently developed a simple fabrication technique, called low one-photon absorption (LOPA) direct laser writing (DLW), to realize multi-dimensional and multi-functional polymer-based photonic submicrostructures. This technique employs a continuous-wave laser at 532 nm-wavelength with only few milliwatts and a simple optical setup, allowing to decrease the cost of the fabrication system by a factor of ten as compared to a commercial DLW system. In this report, we present various photonic structures, such as 2D and 3D micro- resonators, photonic and magnetic submicrostructures, and nonlinear optical structures fabricated by this LOPA- based DLW method. We also discuss about potential applications of those fabricated multi-dimensional and multi-functional photonic submicrostructures in opto-electronics, bio, as well as in opto-mechanics.